Mazda RX8 and proper oil question

[oktobernv]

Hello All.

Rob in Vegas here, got a question.

We have been having a HUGE problem with Mazda RX'8 blowing engines in the Vegas heat this summer.

One dealership alone (Magic Mazda) has already replaced over 20 engines this summer.

These are 2004 RX8's with between 10k and 20k miles on them.

The general theory seems to be that the oil coolers on the cars are not robust enough.

The oil is heating up and eventually turning to sludge. The engine temps are getting WAY high and eventually the APEX seals on the engines are "warping"

Causing a lose of compression and then engine failure.

Mazda ONLY recommends 5w-20 for ALL RX8's

No matter what part of the USA you are in.

This was apparently done to satisfy EPA regulations about emissions with the RX8's.

Mazda does NOT endorse ANY syn oils.

My question is this.

What grade and type of oil would you recommend for HIGH temps like we get in vegas. This summer we had a stretch where temps were between 112-118 for about 2-3 weeks straight.

Most people here do A LOT of city driving. Very little long drives, very little freeway.

Some people have reported engine OIL temps in the RX8's hitting 240+ degrees.

Any thoughts would be much appreciated.

Rob in Vegas.

 

[Leo]

I believe a high % ester oil like Motul 300V would be excellent in those engines. Esters burn clean and don't leave residues which is important for rotaries.

Motul 300V 0W-20 or Redline 0W-20 would be your best bet. They are engineered from the ground up to withstand abuse. My vote goes to Motul however. Also I believe any good syn like Mobil 1 may do the trick but I am not sure how well a PAO product like that will do in regards to burnoff..

 

[berge]

I speak from experience (five blown engines in a 90 rx-7 with tons of track use) when I say that rotaries are a completely different beast than a piston motor. they have ZERO tolerance for pre-ignition(knock), running lean, or overheating. immediate engine damage will result.

I really don't see how the choice of engine oil would have any consequence in these motors failing.

from what I remember, it was common knowledge that the apex seals would give(rebuild time) at anything over 230F. hopefully mazda has substantially upgraded the design specs on these seals because by the end of rotary production, most people I knew with modified rotaries were running race apex seals which withstood more boost/heat etc. but made the compression nonexistant at anything below 3000rpm. aka, horrible street driveability.

yes, I drive a honda now!!

 

[oktobernv]

Thanks for all the QUICK response guys! Much appreciated.

My RX8 engine blew last month - 13k miles on it.

I was running 5w-20. Changing the oil and filter every 3000 miles.

The owners manual says you can go as long as 7500 miles between changes. Obviously that is wrong.

I should have my car back today with the new engine in it.

It will come back to me with the standard 5w-20.

I am going to start doing my oil changes every 1500-2000 miles and see if that helps.

I have also read that if I go with a higher weight oil (10w40 or 20w-50) that those higher weights tend to RAISE the engine temps.

Is that correct?

Because higher temps in the LAST thing I need.

any more thoughts?

Rob in Vegas

 

[berge]

it does not matter if you get an oil that CAN handle the high temps because the apex seals CAN'T.
this is a cooling issue, not oil.

 

[johnd]

Once out of warranty, I'd sure look at an aftermarket oil cooler. I understand Chrysler makes an external oil to water trans cooler that isn't in the radiator, it might be a good bet.

 

[Solo2driver]

A lot of the RX-8 guys are having better luck with RedLine 5w-20 at the recommended drain interval. The Mazda issue with synthetics is from long ago with the original rotaries....I ran my '85 fuel injected 13B with 200K miles running RP 15w-40 synthetic with outstanding UOA numbers and very little wear or consumption. To maintain your warranty, I would use the proper weight 5w-20, but run RedLine or Royal Purple. Rotaries are notoriously tough on oils with all that heat and the rotors being cooled by the oil, as well as having stationary gears.

Other than that, if Mazda is just replacing engines like they used to do on the RX-7's all the time, let them do it until you are out of warranty adn then put a good 15w-40 in there!!!

-JamesW
Rotary Nut

 

[oktobernv]

Hi James

Thanks for the info

I just got off the phone with Mazda USA and asked them if they had changed their stance about the oil type / weight suggestions for the RX8

They said "no."

They said "you can NOT use Syn oil in this engine. It may not cause a problem right away, but it will down the road. The rotary engine NEEDS to burn a bit of oil to run properly."

So it seems that Mazda Corp is DEAD SET AGAINST syn oil in the rotary.

Why is this?

Rob in Vegas

 

[the_oil_dealer]

Screw 5w-20!!! Why would you want to run such a thin oil in a rotary??? I'd go with an HDEo, pref ester based synth!!!

@dino 5w-20 yuk...

 

[Dr. T]

What are they using in Japan?? I'd start with that. Otherwise, why not a synth. 5-40? Or 5-50 for track use?

So retarded to recommend a 5-20 for a sports car....and then there's the Ferrari using 5-20...that's another story

 

[mechtech]

Some BMWs are spec'd for a heavy oil because they found out too late that the bearings were inadequate, or poorly lubed - a patch 'fix'.
Mazda rotaries have always had weak links, and various problems that they dealt with poorly.
Anybody remember the RX7s with anti freeze [ethylene glycol] injected into the rotors to prevent/unstick them?
It seems ludicrous, but it's true.
You have an high performance car, with a genetic defect.
Similar to having a beautiful, smart, funny, girlfriend, [who has an STD].
A good oil may attenuate your problem, but some damage is already done. I'd hit the Mazda forums.

 

[unDummy]

Rotary engines are different and like COOL oil. An average oil temp of 240F is way to hot for a rotary engine. Anything over 220F is a cause for concern.

Have the owners practice a more frequent OCI and not the recommended 7.5k or whatever the manual(or Mazda) recommends.
Only 1/2(if that) of the oil is dumped during an oil change.
I would definitely consider a 3k OCI and even a 2k OCI during hot summer weather.
And above all, make sure these owners keep the oil level topped off "to the top". Too many owners are running it low on oil because of the wide range allowed on the dipstick. Topping off frequently will help prevent oil temperature spiking into the engine death zone. I've met RX-8 owners that didn't even know that the engine was oil injected(must've skipped the owners manual reading). And, they were low on oil

And, if temperature is baking the oil, I would IGNORE the anti-synthetic warning. There are those that use it with no problems. Mazda still hasn't proven the reason why a synth can't be used. Actually, nobody has.

And, if you must extend the OCI(per the owners manual) and use a cheap mineral oil(per Mazda), then let Mazda's warranty replace all these engines. $crew Mazda until they pull their heads out of their a55 and allow the use of synthetics AND thicker oil weights.

Anyone remember the 10w30 non-synth requirement for the '93 twinturbo?? And you wonder why it was only available for 3 years

You'd think Mazda would learn

 

[JohnnyLock]

RP had this to say in its FAQ section -- scroll down and you'll see what they have to say about synthetic in an RX8 or any rotary engine for that matter.

http://www.royalpurple.com/techa/faqsa.html#re0

 

[theguru]

Mazda Oz do sell synthetic oil for the RX-8's here. I have seen it advertised on a poster behind the parts desk last year. It is bottled in Japan. Don't know who the manufacturer is though. Not sure of the grade but I doubt it was a 5w-20.

Mobil recommend 5w-30 or 10w-40, but M1 is not on the list. Shell suggest a 10w-30 syth (blend).

[ August 19, 2005, 08:09 PM: Message edited by: theguru ]

 

[Thatwouldbegreat]

Boy! Mazda is confusing!

They say yse 5W-20 only... don't use synthetics.

Yet all 5W-20's are probably Group III synthetic blends...or fully synthetic.

In Europe they seem to use spec 5W-30 synthetic blend..Mazda Dexelia.

It almost sounds like Mazda rotary engines need an oil tested by Mazda that meets exact target specs for the new RX-8 engine.

 

[mason1125]

I believed the syn oil that 'Theguru' has mentioned is idemitsu oil. It comes with 10W-30 & 20W-50, not 5W-20 though.
More information on the following link:
http://www.idemitsu-usa.com/

I have a RX-8 and have OCI every 2500 miles. Just use Havoline 5W-20 and so far no problem. Just have to top it off every week.

 

[theguru]

Here is some interesting reading from a dealer of their oil.
Warranty

 

[vicmackey]

Considering what has been posted here why on earth would someone want a RX-8?

Sounds like a ticking time bomb to me.

 

[haley10]

240°F and syn not recommended makes it difficult. What oil change intervals are recommended?

Seems like a near impossible situation that Mazda is going to have to address.

 

[Mitch Alsup]

For normal well engineered piston engines, 240dF is NOT too hot, 265dF is borderline too hot and 285dF is definately too hot.

But with engines blowing left and right, I would lookup what the previous versions of that engine (RX7) had as the recommended oil weightings and go from there.